Self-calibrating dosing device

Abstract

A dosing device for bulk material having a dosing scale fastened to an outlet opening of a bulk material container. The dosing device comprises a motor-driven conveyor, extending substantially horizontally, which is designed to convey the bulk material from an entry region to an exit region. The entry region is arranged under the bulk material container. The exit region is supported on at least one first measurement device which is arranged and designed to determine the weight load of the conveyor by the bulk material. The conveyor is attached in a free floating manner to the bulk material container at the entry region thereof.

What is claimed is: 
     
       1. A dosing device for bulk material with a support structure having at least an upper beam and a lower beam and a motor-driven conveyor that is arranged at an outlet opening of a bulk material container and is essentially horizontal,
 wherein the bulk material container is supported on the upper beam of the support structure, 
 wherein the conveyor conveys the bulk material from an entry region to an exit region, 
 wherein the entry region is located beneath the bulk material container, 
 wherein, out of the entry region and the exit region of the conveyor, solely the exit region is supported on the lower beam of the support structure, 
 wherein the exit region is supported on the lower beam by at least one first measuring device, which is arranged and designed so as to ascertain a weight loading of the conveyor by the bulk material, and 
 wherein the conveyor is attached to the bulk material container in a free-floating manner at the entry region. 
 
     
     
       2. The dosing device according to  claim 1 , wherein the conveyor is a screw conveyor, a conveyor belt, a chain conveyor, or a slat conveyor. 
     
     
       3. The dosing device according to  claim 1 , wherein an electronic component is provided that ascertains a mass flow that is conveyed as a function of a sensed weight loading of the conveyor and a speed of the motor drive of the conveyor. 
     
     
       4. The dosing device according to  claim 3 , wherein the electronic component controls a conveying speed of the conveyor such that the conveyed mass flow remains constant. 
     
     
       5. The dosing device according to  claim 1 , wherein the bulk material container is supported on at least one second measuring device that is arranged and designed so as to ascertain a total weight loading of the container and the conveyor caused by the bulk material. 
     
     
       6. The dosing device according to  claim 3 , wherein the electronic component senses a decrease in a total weight loading over time via the second measuring devices and compares it with the bulk material mass conveyed by the conveyor, and if applicable provides a correction factor for ascertaining the conveyed mass flow. 
     
     
       7. The dosing device according to  claim 1 , wherein the bulk material container includes an agitator that is designed to agitate the bulk material. 
     
     
       8. The dosing device according to  claim 5 , wherein the conveyor is suspended in a free floating manner from the bulk material container at the entry region by at least one third measuring device that is arranged and configured so as to sense vertically acting forces between the bulk material container and the conveyor. 
     
     
       9. The dosing device according to  claim 7 , wherein an electronic component is arranged to control the agitator in the bulk material container as a function of the measured vertically acting forces such that a homogeneous flow behavior is established in the bulk material container. 
     
     
       10. A method for operating a dosing device for bulk material according to  claim 1 , the method comprising:
 a) measuring the weight loading of the conveyor solely via the at least one first measuring device; 
 b) ascertaining the mass flow of the bulk material conveyed in the conveyor from a conveyor speed and the weight loading of the conveyor and from a correction factor; 
 c) comparing the ascertained mass flow with a predetermined nominal value for the mass flow; and 
 d) adjusting the conveyor speed of the conveyor as a function of the comparison between the ascertained mass flow and the predetermined nominal value for the mass flow. 
 
     
     
       11. The method according to  claim 10 , wherein a cyclically repeating control measurement is performed during operation of the dosing device, comprising the following steps:
 i) measuring the total weight loading of the bulk material container and the conveyor via at least one second measuring device; 
 ii) ascertaining a decrease in total weight loading during a defined time period; 
 iii) ascertaining a bulk material mass conveyed during the defined time period by the conveyor; 
 iv) ascertaining a correction value from the quotient of the ascertained decrease in total weight loading and the ascertained bulk material mass conveyed by the conveyor; and 
 v) adjusting the correction value for step b). 
 
     
     
       12. A method for providing an agitator regulation for operating a dosing device for bulk material according to  claim 1 , the method comprising:
 1) measuring vertical forces via at least one additional measuring device acting between the bulk material container and the conveyor; 
 2) ascertaining and analyzing a signal behavior over time of the measured vertical forces; and 
 3) adjusting an agitator speed of the agitator in the bulk material container as a function of the ascertained and analyzed signal behavior. 
 
     
     
       13. A dosing device for bulk material comprising:
 a support structure having at least an upper beam and a lower beam; 
 a bulk material container supported on the upper beam of the support structure, the bulk material containing having an outlet opening; 
 a conveyor arranged at the outlet opening of a bulk material container, the conveyor having an entry region that receives the bulk material from the bulk material container and an exit region where the bulk material exits the conveyor, the conveyor at least partly supported by the lower beam of the support structure; 
 wherein, out of the entry region and the exit region of the conveyor, solely the exit region is supported on the lower beam of the support structure, 
 wherein the exit region of the conveyor is supported on the lower beam by at least one bearing device that measures a weight loading of the conveyor by the bulk material.